The present invention relates generally to an article of footwear, and in particular to an article of footwear with an air bladder.
Articles of footwear with bladders or other similar structures that are located in the heel area of a shoe have been proposed. These bladders are typically positioned in one or more cavities found in the midsole and/or insole of a shoe and are often used in combination with a cushioning element. Some of these known bladder elements may be transparent. For example, Tawney et al. (U.S. Pat. No. 5,685,090) is directed to a cushioning system for a shoe sole that includes an inflatable air bladder in the heel of a shoe that is positioned in a cavity in the midsole. An upper with a lasting sock covers the air bladder, both of which may be transparent. An opening may be formed in the outsole layer so that the bladder element is visible from the bottom of the shoe. Likewise, Allen et al. (U.S. Pat. No. 5,985,383) is directed to a foam footbed that includes a viscoelastic polymer plug in the heel area of a shoe. The plug is embedded in and generally surrounded by a non-woven textile layer which, in turn, is positioned within a foam layer of the shoe midsole. The textile layer extends horizontally in an upper part of the footbed and then vertically downward into the midsole in the heel area of the shoe. A layer, such as leather, covers the horizontal portions of the non-woven textile layer, leaving the top portion of the plug exposed. A gel bladder and window may be positioned in the bottom layer beneath the heel plug.